class PMS::Proxy

# File lib/pms/proxy.rb, line 33
def initialize(pms)
  @pms     = pms
  @index   = pms.index
  @results = pms.results
end

# File lib/pms/proxy.rb, line 39
def matches
  index.matches(results)
end

# File lib/pms/proxy.rb, line 78
def apply_operator(op, doc_nums)
  results = self.results

  case op = op.to_s.downcase
    when 'and' then results &= doc_nums
    when 'or'  then results |= doc_nums
    when 'not' then results -= doc_nums
    else raise ArgumentError, "invalid operator `#{op}'"
  end

  clone_with_results(results)  # allow chaining!
end

# File lib/pms/proxy.rb, line 71
def apply_operator_with_block(op)
  case sub = yield(pms)
    when Proxy then apply_operator(op, sub.results)
    else raise "sub-query must return a #{Proxy} object (got #{sub.class})"
  end
end

# File lib/pms/proxy.rb, line 67
def apply_operator_with_token(op, token)
  apply_operator(op, index.results(token))
end

# File lib/pms/proxy.rb, line 91
def clone_with_results(results)
  clone.tap { |clone| clone.instance_variable_set(:@results, results) }
end